1. The skill tree in idols amount to this (off the top of my head):
Unique burst skill. There are 3 levels, so you need to get it 3 times to get level 3. Each one (Basically it looks like an idol image on the grid.) gives +1 to the level, or grants it if you get it the first time.
+ voltage on regular notes. So when you hit that particular skill note type (VO, DA, VI), you will gain more voltage per hit.
+ voltage on appeal. These are across all idols, and no idol gets more appeal than another when maxed. I think they also affect the amount of damage on the rival.
+1 to appeal combos. There are two, and they allow duo and trio appeals.
+1 to burst combos. These allow duo and trio bursts.
+ Counter appeal - Allows the idol to counter appeal. Pretty sure they're across all idols, but some get it earlier than others. I think this is bundled up with burst appeal.
The flexiblity is pre level 35, where you get to skewer your idol's growth.
2. Yes, I outlined how they stacked up previously. This is within the idol set, and between other idols.
3. They all stack. Only one idol needs access to it for that unit to have access to duo+ appeals, bursts and the ability to counter burst to grant it to the team though. This is useful for All stars early on - you make your initial team of 3 have access to the triple appeal/burst, and spread 1 per team.
4. There are two stores. BK Maniac and Lucky Rabbit.
Each one will only show so many costumes and so many accessories. You must buy the ones on offer before others will show up in their place.
5. Appeal skills are shared through the unit as it is assumed the team is involved at all times.
Burst skills will only activate if the idol in question is involved in them. So a solo burst will use the skill of the person bursting, where a triple burst will use all 3 (with a multiplier).
Sorry, I've got another set of questions.... You can be very brief in the answers.
1. From looking at Miki and Yukiho's skills board in the English wikia, I just realize most skills are shared among idols generally speaking.
In that case are these the uniques skills for the idols (see below)? Why are there different ranks for same unique skills for each idol?
2. Also, do skills stack up? I've noticed repeated skills in the same idol.
3. I know burst counter, memory/burst duo(trio) are shared among idols. What about skills like score up or rate up? Is that shared or does that idol have to be the leader?
4. Are memory appeal or burst appeal skills shared? Or is it specific to that idol in that the idol has to be part of the memory/burst appeal to activate that memory/burst skill?
5. The Extend costumes are not showing up in the shops. Is my produce rank too low (rank 4)?